Green Tea May Help Prevent Glaucoma

Glaucoma is one of the leading causes of blindness in the U.S., according to the National Institutes of Health. It comes like a silent thief, gradually stealing sight and usually providing no warning symptoms in the early stages. But as the disease progresses, damage to the optic nerve grows worse and side vision can gradually fail until there’s only tunnel vision left, and then no vision at all.

Treatment with drugs and surgery may slow down the eyesight deterioration but there’s no cure. However, new research provides evidence there’s a natural way to prevent glaucoma from developing in the first place — drink green tea regularly.

A study just published in the American Chemical Society’s Journal of Agricultural and Food Chemistry concludes that phytochemicals found in green tea actually penetrate deeply into tissues of the eyes. This is the first report to document how the lens, retina and other parts of the eye absorb the powerful antioxidants and disease-fighting substances found in green tea, and it strongly raises the possibility that green tea can prevent glaucoma as well as other eye diseases and conditions.

Scientist Chi Pui Pang, Ph.D., of the department of ophthalmology and visual sciences at the Chinese University of Hong Kong, and his colleagues pointed out in a statement to the press that green tea contains flavonoids known as catechins that are thought to protect the eyes. But until now, there was doubt that catechins could pass through the stomach and gastrointestinal tract and end up in eye tissues. However, in experiments with laboratory rats, the scientists showed conclusively that after green tea is consumed, structures in the eye absorb sight-protecting green tea catechins.

When the scientists analyzed the eye tissues of the animals used in their study, they discovered that various eye structures had absorbed significant amounts of individual catechins. For instance, the retina took in the highest levels of a catechin known as gallocatechin and the aqueous humor (a thick watery substance that fills the space between the lens and the cornea) soaked up another green tea phytochemical dubbed epigallocatechin.